The present invention relates to vehicle restraints generally and to a seat belt retractor having means for absorbing a certain amount of energy during a crash by deforming and/or crushing internal parts and therefor limiting the energy imparted to an occupant to lower the potential for injury.
Safety belt restraint system (or sub-systems) and air bag systems (or sub-systems) are often designed to meet separate and distinct safety criteria and performance standards and then these separately designed systems are used together as a combined system to provide occupant protection during vehicle crashes and accidents. The performance of these systems, in terms of known, measurable occupant injury performance standards such as head injury criteria (HIC) and resultant chest acceleration may not necessarily be equal to or less than the performance of either individual sub-system. It is believed that the degradation in performance, as manifested by increased occupant chest acceleration and related chest loading, is the result of an effective increased stiffness afforded by the seat belt system working in concert with the air bag system. These injury criteria and the potential for actual injury can be reduced by introducing into the seat belt safety system an energy absorbing device which absorbs a certain amount of the energy produced in a crash or other emergency driving condition and in so doing lessens the amount of energy that could be absorbed by the occupant thereby lessening the potential for occupant injury.
It is an object of the present invention to provide an improved occupant protection system and more specifically an energy absorbing retractor. The invention herein describes a method and apparatus for improving occupant performance by reducing the potential for injuries. The present invention comprises: a load absorbing retractor comprising: a rotating spool or reel, seat belt webbing secured to the reel; first means, responsive to loads generated during an emergency situation, for deforming a portion of the reel and in so doing dissipating a determinable amount of the energy and hence limiting the loads transmitted to an occupant.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.